Rolling element bearings comprise, as bearing rings that can rotate opposite each other, an inner ring and an outer ring. Different bearing applications require, for example, the detection of rotational speed and direction of rotation or other monitoring tasks of the rotating bearing part. These and other tasks require electronic components, such as sensors, actuators, processors, and data memories.
From the prior art it is known to use generators in rolling element bearings that provide the necessary energy to the electronic components present there with little expense. There are solutions that use so-called claw-pole alternators. Known claw-pole alternators comprise a first claw ring with a sequence of first claws running in the circumferential direction of the rolling element bearing, a second claw ring with a sequence of second claws running in the circumferential direction of the rolling element bearing, and an induction coil that is surrounded by the two claw rings and surrounds the rotational axis of the rolling element bearing. The claw pole rings are arranged offset relative to each other in the circumferential direction. The claw-pole alternator further comprises a sequence of magnetic poles running in the circumferential direction. If a first claw of the first claw ring is opposite a first pole, for example, a north pole, a magnetic circuit is formed via a second claw of the second claw ring adjacent in the circumferential direction to a second, complementary magnetic pole, in this case a south pole, which is adjacent in the circumferential direction and surrounds the induction coil. If the bearing ring with the two claw rings continues to rotate, the second claw is opposite a north pole and the first claw is opposite a south pole, so that the direction of the magnetic circuit surrounding the induction coil reverses and an electric voltage is induced in the induction coil.
DE 10 2011 075 548 A1 describes a bearing with a first and a second bearing ring and an energy generating unit formed as a claw-pole alternator. The claw-pole alternator comprises a first claw ring with a sequence of first claws and a second claw ring offset in the circumferential direction of the rotational axis with a sequence of second claws. The two claw rings surround an induction coil surrounding the rotational axis. Claw rings and induction coils are mounted with a first carrier ring on an end face of the first bearing ring. A sequence of magnetic poles surrounding the rotational axis is mounted by means of a second carrier ring on the end face of the second bearing ring. The magnetic poles are connected to each other in a magnetically conductive manner by a yoke ring made from a magnetically conductive material. The two claw rings are connected in a magnetically conductive manner with the help of a flux conducting ring.
In DE 10 2009 031 609 A1, a rolling element bearing with a claw-pole alternator arranged between a first and second bearing ring is described. The claw-pole alternator comprises a sequence of magnetic pole pairs wrapping around the circumference of the second bearing ring, a claw ring mounted on the first bearing ring with a sequence of claws wrapping around a circumference of the first bearing ring, and a magnetic induction coil. A first claw of the claw ring is arranged in magnetically conductive connection to a magnetically conductive section of the body of the first bearing ring. The magnetic poles of the pole pairs are arranged in magnetically conductive connection to a magnetically conductive section of the body of the second bearing ring. The magnetic circuit is closed by the two magnetic sections and the rolling element body.
DE 10 2010 022 369 A1 shows a rolling element bearing with a claw-pole alternator arranged between the first and second bearing ring. The claw-pole alternator comprises a sequence of magnetic poles wrapping around the first bearing ring, a sequence of magnetically conductive claws wrapping around the second bearing ring, and an induction coil that is arranged on a cage used for holding the rolling element body.
DE 10 2011 075 547 A1 includes a rolling element bearing with a claw-pole alternator that is arranged between the first and second bearing ring and whose magnetic poles are arranged on a cage used for holding the rolling element bodies.
DE 10 2011 082 804 A1 is designed with a rolling element bearing with integrated claw-pole alternator comprising a first claw ring with a sequence of first claws and a second claw ring offset in the circumferential direction of the rotational axis of the bearing with a sequence of second claws. The claw rings surround an induction coil surrounding the rotational axis. Claw rings and induction coils are mounted on an end face of a first bearing ring. A sequence of magnetic poles is mounted on a second bearing ring and connected to each other in a magnetically conductive manner by means of a yoke ring made from a magnetically conductive material. The two claw rings are connected in a magnetically conductive manner by a magnetically conductive section of an axial fastening element, in particular, by a lock nut or slotted nut.
Previously known solutions use claw-pole alternators that are arranged around the entire circumference of the rolling element bearing. In this way, they are depending on the diameter of the rolling element bearing and cannot be used universally.
DE 10 2010 021 159 A1 shows a rolling element bearing with a salient pole machine with a primary part and a secondary part that are each connected locked in rotation to one of the bearing rings. The secondary part is formed by permanent magnets that are arranged with alternating polarity in the circumferential direction of the bearing ring. The generator has a modular design so that it can be integrated into different bearing types. To do this, the permanent magnets are embedded in a secondary carrier. The primary part comprises salient poles each with an individual pole winding that are embedded in a primary carrier. Primary and secondary carriers must be designed so that they can be finished to form the generator independent of the final installation diameter. The primary and secondary parts must not extend past the entire circumference of a rolling element bearing, but instead can also extend in some sections between the bearing rings. In this case, a compensating weight must be provided on the diametrically opposite section of the generator. Alternatively, a second generator could also be provided in an opposite arrangement.